Thermoelectric power generation is drawing more and more interest in engine exhaust heat recovery to improve fuel efficiency.1 The development of useful devices requires materials with high dimensionless figure of merit zT (zT=S2T/ρκ, S being Seebeck coefficient, ρ electric resistivity and κ thermal conductivity).2 Among the materials suitable for power generation applications PbTe has been the most studied,3, 4 including recent results from nanostructuring5 and band modification6 with exceptional zT in both n type7, 8 and p type.9, 10 
PbSe, closely related to PbTe, is much less frequently considered for thermoelectrics. This can be traced to the smaller band gap and higher thermal conductivity expected from the lighter PbSe compared with PbTe.11 Importantly, PbSe offers a cheaper alternative to PbTe, as Se is more abundant and the cost is much less than that of Te. Thus, there is a need in the art for PbSe with high thermoelectric performance.